UnevenArthur Thomas, Gemstones (2009), UnevenArthur Thomas, Gemstones (2009), Conchoidal, Brittle
Uneven, Uneven, ConchoidalGemdat.org, Management Team (2012)
Ca 2Mg 5Si 8O 22(OH) 2Ulrich Henn and Claudio C.
Mn 3Al 2(SiO 4) 3Arthur Thomas , Gemstones (2009)